CN115259335A - A kind of wastewater acid-base neutralization control method and logic setting module - Google Patents

Abstract

The invention belongs to the technical field of debugging and operation of a chemical water system of a nuclear power plant, and particularly relates to a wastewater acid-base neutralization control method and a logic setting module, which are used for controlling wastewater acid-base neutralization equipment of the chemical water system of the nuclear power plant, wherein a wastewater pool (16) is arranged in the wastewater acid-base neutralization equipment, and the method comprises the following steps: step S1, calculating the volume of the wastewater in a wastewater pool (16), and stirring the wastewater; s2, judging the pH value of the wastewater, and adding a set amount of concentrated alkali into the wastewater when the pH value is less than 6; when the pH value is more than 9, adding a set amount of concentrated acid into the wastewater; when the pH value is more than or equal to 6 and less than or equal to 9, the wastewater is discharged from the wastewater pool (16). According to the invention, the acid-base neutralization operation can be rapidly completed by accurately controlling the set amount of the required concentrated acid-base solution, the wastewater discharge efficiency is improved, the manpower input is greatly reduced, and the use amounts of concentrated acid and concentrated base are saved.

Description

A wastewater acid-base neutralization control method and logic setting module

technical field

The invention belongs to the technical field of commissioning and operation of a chemical water system of a nuclear power plant, and in particular relates to a waste water acid-base neutralization control method and a logic setting module.

Background technique

During the commissioning and operation of the desalinated water production system, condensate polishing system, and circulating water treatment system of nuclear power plants, concentrated strong acid and strong alkali solutions will be used, resulting in acid and alkaline wastewater, and strong acid and strong alkali solutions H ⁺ and OH ^- are in a fully ionized state. The wastewater neutralization device mainly includes wastewater pumps, wastewater tanks, agitators, remote pH meters, concentrated acid metering boxes, concentrated alkali metering boxes and their associated pneumatic valves, pipelines, and PLC control equipment for supporting chemical systems.

Wastewater is uniformly collected in the wastewater neutralization tank, and the pH is adjusted by strong acids and alkalis such as concentrated sulfuric acid, concentrated hydrochloric acid, and concentrated sodium hydroxide solution until the pH value of the waste liquid reaches between 6 and 9, and then discharged from the neutralization tank. When the original waste water is emptied, new waste water is received. So reciprocating operation.

Since the pH adjustment process is a nonlinear process, subject to the monitoring characteristics of pH sample water and the working principle of the pH meter, the pH meter display value still has a certain hysteresis, and has high sensitivity near the neutral point of pH Simple PLC logic editing language is difficult to realize more complex logic settings. The actual wastewater acid-base neutralization process is performed manually. The entire process takes a long time, the consumption of concentrated acid and concentrated alkali is large, and a lot of repetitive work often fails to achieve good results. Wastewater discharge is inefficient and sometimes restricts the normal operation of the entire system.

Contents of the invention

The purpose of the present invention is to provide a method for controlling the acid-base neutralization of waste water, which can improve the utilization rate of acid and lye, reduce the harm to the environment and save manpower and material costs.

In order to achieve the above object, the technical solution adopted in the present invention is a method for controlling acid-base neutralization of waste water, which is used for the control of acid-base neutralization equipment of waste water in the chemical water system of a nuclear power plant. There is a waste water pool, which also includes an acid metering box for injecting concentrated acid into the waste water pool and an alkali metering box for injecting concentrated alkali into the waste water pool, and the method includes the following steps:

Step S1, the program calculates the volume Vwastewater of the _waste water in the waste water pool, and stirs the waste water;

Step S2, read the pH value of the waste water, when the pH value is <6, calculate the set amount of the required concentrated alkali solution, add the set amount of concentrated alkali solution to the waste water, so that the alkali metering The liquid level of tank drops to set value; When described pH value＞9 time, calculate the set amount of required concentrated acid solution, add the set amount of concentrated acid in described waste water, make described acid metering box ( 14) the liquid level drops to the set value; when 6≤the pH value≤9, the waste water is discharged from the waste water pool.

further,

The waste water acid-base neutralization equipment also includes a liquid inlet pipe and a liquid discharge pipe connected to the waste water tank, the liquid inlet pipe is provided with a liquid inlet valve, and the liquid discharge pipe is provided with a liquid discharge valve and a waste water discharge pipe in series. pump, the discharge valve is close to the water outlet end of the discharge pipe;

setting a pH meter on the drain pipe between the drain valve and the waste water pump;

Also comprising a circulation pipe, the top of the circulation pipe is connected on the drain pipe between the drain valve and the pH meter; the bottom end of the circulation pipe is provided with an agitator, and the agitator Located in the waste water pool; the circulation pipe is provided with a recirculation valve;

A waste water level gauge is provided on the waste water pool;

It also includes an acid metering box provided with a first acid inlet pipe, a second acid inlet pipe and an acid liquid level gauge, the second acid inlet pipe is connected to the waste water pool; the first acid inlet pipe is provided with The first acid inlet valve, the second acid inlet valve is provided on the second acid inlet pipe;

It also includes an alkali metering box provided with a first alkali inlet pipe, a second alkali inlet pipe and an alkali liquid level gauge, the second alkali inlet pipe is connected to the waste water pool; the first alkali inlet pipe is provided with The first alkali inlet valve, the second alkali inlet valve is provided with a second alkali inlet valve;

There are multiple waste water pools, which serve as backups for each other. When one of the waste water pools performs acid-base neutralization operation, the rest of the waste water pools can receive the waste water.

Further, in the step S1, it specifically includes:

Step S1.1, the operator on duty manually triggers the waste water acid-base neutralization procedure;

Step S1.2, closing the liquid inlet valve and the liquid discharge valve, and opening the recirculation valve;

Step S1.3, open the first acid inlet valve and the first alkali inlet valve, and close the first acid inlet valve when the acid liquid level gauge has a high liquid level alarm; When a high liquid level alarm occurs on the liquid level gauge, close the first alkali inlet valve;

Step S1.4, start the wastewater pump, stir and mix the wastewater in the wastewater pool with the agitator until the pH value is stable, the pH value refers to the pH displayed on the pH meter value.

Further, in the step S2, it specifically includes:

Step S2.1, judging according to the execution conditions of the pH value, when the pH value is <6, open the second alkali inlet valve, and add a set amount of lye to the waste water pool; when the pH value is When >9, open the second acid inlet valve and start adding a set amount of acid solution to the waste water pool; when 6≤the pH value≤9, open the drain valve and close the recirculation valve, the waste water pond starts to discharge the waste water;

Step S2.2, when the waste water level gauge has a low liquid level alarm, turn off the waste water pump;

Step S2.3, the waste water pool is in standby state.

Further, in the step S1.2, the waste water in the waste water pool performing the acid-base neutralization operation is kept in a relatively stable state, and according to the liquid level of the waste water, the mathematical model formula is used to calculate waste water volume;

Wastewater volume V _{waste water} = S _{waste water pool} × H _{waste water} ;

S _{waste water} refers to the sectional area of described waste water pool;

H _{waste water} refers to the liquid level height of waste water.

Further, in the step S1.3, the acid metering box and the alkali metering box contain enough concentrated acid and concentrated alkali for an acid-base neutralization operation; during the acid-base neutralization process, If a low liquid level alarm occurs in the acid metering box or the alkali metering box, the concentrated acid or the concentrated alkali will be automatically replenished into the acid metering box or the alkali metering box.

Further, in the step S2.1, the concentration of the hydrogen ion substance and the concentration of the hydroxide ion substance in the waste water of the waste water pond and the required amount of the concentrated alkali and the The volume of concentrated acid, and by calculating the liquid level height of described waste liquid, control the required consumption of described concentrated acid and described concentrated alkali; Concrete mathematical model formula is as follows:

Concentration of hydrogen ion species in concentrated acid:

Concentration of hydroxide ion species in concentrated alkali:

in,

ρ _{Concentrated acid} refers to the density of concentrated acid at 20°C;

ρconcentrated _alkali refers to the density of concentrated acid at 20°C;

W% refers to the mass fraction of solute in concentrated acid or the mass fraction of solute in concentrated alkali;

M _{concentrated acid} refers to the molar mass of concentrated acid;

M _{concentrated alkali} refers to the molar mass of concentrated alkali;

When reaching the pH neutral point, when the pH value is 7, [H ⁺ ]=[OH ^- ]=1×10 ^-7 mo/L;

Before the acid-base neutralization operation, the concentrated acid and the concentrated alkali first flow into the acid metering box and the alkali metering box, and are controlled by the liquid levels of the acid metering box and the alkali metering box The required amount of the concentrated acid and the concentrated alkali, the acid metering box and the alkali metering box are standard cylindrical;

When the waste liquid pH<7, add alkali for neutralization, the volume of the concentrated alkali needs to be added:

When the waste liquid pH>7, add acid to neutralize, need to add the volume of described concentrated acid:

Waste liquid pH refers to the pH value shown in the pH meter;

是指酸碱中和操作之前所述废水中的氢离子物质浓度；

refers to the concentration of hydrogen ion substances in the wastewater before the acid-base neutralization operation;

是指酸碱中和操作之前所述废水中的氢氧根离子物质浓度；

Refers to the concentration of hydroxide ion substances in the wastewater before the acid-base neutralization operation;

是指中和状态下所述废水中的氢离子物质浓度；

refers to the concentration of hydrogen ion substances in the wastewater in a neutralized state;

是指中和状态下所述废水中的氢氧根离子物质浓度；

Refers to the concentration of hydroxide ion substances in the wastewater in a neutralized state;

是指浓酸中氢离子物质浓度；

Refers to the concentration of hydrogen ion species in concentrated acid;

是指浓碱中氢氧根离子物质浓度；

Refers to the concentration of hydroxide ion species in concentrated alkali;

Also includes the bias constant K _bias

V _{Actual liquid volume} refers to the volume of concentrated acid and concentrated alkali required in the actual acid-base neutralization operation;

V _{Theoretical liquid volume} refers to the volume of concentrated acid and concentrated alkali required in the calculation of acid-base neutralization operation;

The K _bias is 1.09.

Further, in the step S2.2, during the waste liquid discharge process, the pH value is always monitored, and when the pH value changes, the recirculation valve is opened, the drain valve is closed, and then closed again The waste water pump.

In order to achieve the above purpose, the present invention also discloses a logic setting module for acid-base neutralization of waste water in a control method for acid-base neutralization of waste water. In the PLC program, in the step S2, the logic setting module performs logic operations to calculate the set amount of the required concentrated alkali solution and the set amount of the required concentrated acid solution;

The logic setting module includes a first submodule and a second submodule;

The first submodule is used to control the PLC program to implement steps S1.2, S1.3, and S1.4; the mathematical model formula in the step S1.2 is set in the first submodule;

The second sub-module is used to control the PLC program to implement step S2.1 and step S2.2; the mathematical model formula in the step S2.1 is set in the second sub-module.

The beneficial effects of the present invention are:

The wastewater acid-base neutralization control method provided by the present invention can significantly improve the pH adjustment efficiency of the wastewater in the wastewater pool 16, realize 1-2 cycles, and complete the discharge of wastewater from the entire pool. Shorten the operation time of wastewater neutralization, improve the efficiency of wastewater discharge, greatly reduce the input of manpower, and save the consumption of concentrated acid and concentrated alkali.

Description of drawings

Fig. 1 is a logical schematic diagram of a kind of waste water acid-base neutralization control method described in the specific embodiment of the present invention;

Fig. 2 is the schematic diagram of the wastewater acid-base neutralization equipment of the chemical water system of the nuclear power plant described in the specific embodiment of the present invention;

In the figure: 1-liquid inlet valve, 2-liquid discharge valve, 3-recirculation valve, 4-first acid inlet valve, 5-first alkali inlet valve, 6-wastewater pump, 7-second alkali inlet valve, 8-second acid inlet valve, 9-acid liquid level gauge, 10-lye liquid level gauge, 11-pH meter, 12-wastewater level gauge, 13-agitator, 14-acid metering box, 15-alkali Metering box, 16-wastewater tank, 17-inlet pipe, 18-drainage pipe, 19-circulation pipe, 20-first acid inlet pipe, 21-first alkali inlet pipe, 22-second acid inlet pipe, 23 -Second alkali inlet pipe.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

The present invention provides a wastewater acid-base neutralization control method, which is used for the control of wastewater acid-base neutralization equipment in the chemical water system of a nuclear power plant (including a nuclear power plant condensate polishing system, an electrolytic chlorine production system, and a desalinated water production system. waste water acid-base neutralization work, or the waste water acid-base neutralization operation of similar structure), waste water acid-base neutralization equipment (as shown in Figure 2) is provided with waste water pond 16, also comprises the inlet that is connected on waste water pond 16 A liquid pipe 17 and a liquid discharge pipe 18, a liquid inlet valve 1 is provided on the liquid inlet pipe 17, a liquid discharge valve 2 and a waste water pump 6 are arranged in series on the liquid discharge pipe 18, and the liquid discharge valve 2 is close to the water outlet end of the liquid discharge pipe 18;

A pH meter 11 is set on the drain pipe 18 between the drain valve 2 and the waste water pump 6;

Also comprise circulation pipe 19, the top of circulation pipe 19 is connected on the drain pipe 18 between drain valve 2 and pH meter 11; Middle; the circulation pipe 19 is provided with a recirculation valve 3;

The waste water tank 16 is provided with a waste water level gauge 12;

Also include the acid metering tank 14 (for injecting concentrated acid into the waste water pool 16) that is provided with the first acid inlet pipe 20, the second acid inlet pipe 22 and the acid liquid level gauge 9, the second acid inlet pipe 22 is connected with the waste water The pools 16 are connected; the first acid inlet pipe 20 is provided with a first acid inlet valve 4, and the second acid inlet pipe 22 is provided with a second acid inlet valve 8;

Also comprise the alkali metering box 15 that is provided with the first alkali inlet pipe 21, the second alkali inlet pipe 23 and the lye level gauge 10 (for injecting concentrated alkali in the waste water pool 16), the second alkali inlet pipe 23 and waste water The pools 16 are connected; the first alkali inlet pipe 21 is provided with a first alkali inlet valve 5, and the second alkali inlet pipe 23 is provided with a second alkali inlet valve 7;

There are multiple waste water pools 16, which serve as backups for each other. When one waste water pool 16 performs an acid-base neutralization operation, the rest of the waste water pools 16 can receive waste water and are redundantly set.

The wastewater acid-base neutralization control method comprises the following steps:

Step S1, the program calculates the volume V of the _waste water in the waste water pool 16, and fully stirs the waste water;

Step S2, read the pH value of the waste water, when the pH value is <6, calculate the set amount of the required concentrated alkali solution, add the set amount of concentrated alkali to the waste water, so that the liquid level of the alkali metering tank 15 drops to the set value; when the pH value＞9, calculate the set amount of the required concentrated acid solution, add the set amount of concentrated acid in the waste water, so that the liquid level of the acid metering tank 14 drops to the set value; when 6 When ≤pH value≤9, the waste water is discharged from the waste water pool 16 .

As shown in Figure 1, in step S1, specifically include:

Step S1.1, the operator on duty manually triggers the waste water acid-base neutralization procedure;

Step S1.2, close the liquid inlet valve 1 and the liquid discharge valve 2, and open the recirculation valve 3; the waste water pool 16 is isolated separately, and no new waste liquid enters the waste water pool 16 during the process of acid-base neutralization (pH stability adjustment) , and no waste liquid is discharged, and the waste water is in a relatively stable state;

Step S1.3, open the first acid inlet valve 4 and the first alkali inlet valve 5 (the acid metering box 14 starts to prepare acid, and the alkali metering box 15 starts to prepare alkali), when the acid liquid level gauge 9 has a high liquid level alarm , close the first acid inlet valve 4; when the lye liquid level gauge 10 has a high liquid level alarm, close the first alkali inlet valve 5;

Step S1.4, start the wastewater pump 6, and stir and mix the wastewater in the wastewater pool 16 with the agitator 13 until the pH value is stable, and the pH value refers to the pH value shown in the pH table 11.

As shown in Figure 1, in step S2, specifically include:

Step S2.1, after the value of the pH meter 11 is stable, judge according to the execution conditions of the pH value, when the pH value is <6, open the second alkali inlet valve 7, and add a set amount of lye to the waste water pool 16; When >9, open the second acid inlet valve 8, start to add a set amount of acid solution to the waste water pool 16; when 6≤pH value≤9, open the drain valve 2, close the recirculation valve 3, and the waste water pool 16 starts external waste water;

Step S2.2, when the waste water level gauge 12 has a low liquid level alarm, turn off the waste water pump 6;

Step S2.3, the waste water pool 16 is in standby state.

In step S1.2, make the waste water in the waste water pool 16 performing the acid-base neutralization operation be in a relatively stable state, and calculate the waste water volume according to the liquid level height of the waste water through a mathematical model formula;

Wastewater volume V _{waste water} = S _{waste water pool} × H _{waste water} ;

S _{waste water} refers to the cross-sectional area of waste water pond 16;

H _{waste water} refers to the liquid level height of waste water, the cross-section of the waste water pool 16 is a regular rectangle, and the cross-sectional area S _{waste water} can be calculated in advance.

In step S1.3, the acid metering box 14 and the alkali metering box 15 contain enough concentrated acid and concentrated alkali of the required amount for an acid-base neutralization operation; in the acid-base neutralization process, if the acid metering box 14 or Alkali metering box 15 occurs liquid level low alarm, then will replenish concentrated acid or concentrated alkali automatically in acid metering box 14 or alkali metering box 15.

In step S2.1, by mathematical model formula, calculate the concentration of hydrogen ion substance and the concentration of hydroxide ion substance in the waste water of waste water pond 16 and the volume of the concentrated alkali of required amount and concentrated acid, and by calculating the waste liquid The liquid level controls the required amount of concentrated acid and concentrated alkali; the specific mathematical model formula is as follows:

Concentration of hydrogen ion species in concentrated acid:

Concentration of hydroxide ion species in concentrated alkali:

in,

ρ _{Concentrated acid} refers to the density of concentrated acid at 20°C;

ρconcentrated _alkali refers to the density of concentrated acid at 20°C;

W% refers to the mass fraction of solute in concentrated acid or the mass fraction of solute in concentrated alkali;

M _{concentrated acid} refers to the molar mass of concentrated acid;

M _{concentrated alkali} refers to the molar mass of concentrated alkali;

For example: the acid and alkali solutions used in water treatment in nuclear power plants mainly include concentrated hydrochloric acid, concentrated sulfuric acid, and concentrated sodium hydroxide. Both are strong acid and strong alkaline solutions, and the hydrogen ions and hydroxide ions are in a completely electrolytic state. For the convenience of understanding and calculation, 31% concentrated hydrochloric acid and 32% concentrated sodium hydroxide solution are used to demonstrate and calculate the concentration of hydrogen ions and hydroxide ions in the solution.

ρconcentrated _{hydrochloric acid} : the density of concentrated hydrochloric acid solution, at 20°C, the density is 1.155Kg/L; ρconcentrated _alkali : the density of concentrated alkali solution, at 20°C, the density is 1.349Kg/L;

The pH value is a measure of the acidity and alkalinity of the solution. The pH value is the negative logarithm of the hydrogen ion concentration per liter of the solution. The shape of the pH neutralization curve is related to the dissociation constant of the acid-base in the solution. The acid-base neutralization reaction is a reversible reaction. When the chemical forward and reverse reaction rates are equal, it is in a chemical equilibrium state; the concentration of hydrogen ions and hydroxide ions in water is the same, and the ionization equilibrium constant of water at 25°C is K _w ;

K _w =[H ⁺ ]×[OH ^- ]=1×10 ^-14

When reaching the pH neutral point, when the pH value is 7, [H ⁺ ]=[OH ^- ]=1×10 ^-7 mo/L;

Due to the high concentration of concentrated acid\concentrated alkali, the amount needed for each neutralization operation is relatively small, so before the acid-base neutralization operation, the concentrated acid and concentrated alkali first flow into the acid metering box 14 and the alkali metering box 15. Control the required amount of concentrated acid and concentrated alkali through the liquid level height of the acid metering box 14 and the alkali metering box 15, the acid metering box 14 and the alkali metering box 15 are standard cylindrical shapes;

When the pH of the waste liquid is less than 7, add alkali to neutralize, and the volume of concentrated alkali needs to be added:

When the pH of the waste liquid is more than 7, add acid to neutralize, and the volume of concentrated acid needs to be added:

Waste liquid pH refers to the pH value shown in pH Table 11;

是指酸碱中和操作之前废水中的氢离子物质浓度，

It refers to the concentration of hydrogen ion substances in the wastewater before the acid-base neutralization operation,

是指酸碱中和操作之前废水中的氢氧根离子物质浓度，

Refers to the concentration of hydroxide ion substances in the wastewater before the acid-base neutralization operation,

是指中和状态下废水中的氢离子物质浓度，

It refers to the concentration of hydrogen ion substances in the wastewater in the neutral state,

是指中和状态下废水中的氢氧根离子物质浓度；

Refers to the concentration of hydroxide ion substances in the wastewater in a neutralized state;

是指浓酸中氢离子物质浓度；

Refers to the concentration of hydrogen ion species in concentrated acid;

是指浓碱中氢氧根离子物质浓度；

Refers to the concentration of hydroxide ion species in concentrated alkali;

It also includes the _deviation of the deviation constant K. In the process of actual wastewater neutralization, due to the influence of residual liquid in the pipeline, residual liquid in the metering tank, deviation of the liquid level gauge, and construction deviation of the waste water tank, the concentrated acid-base solution required for actual neutralization is different from the calculation There will be deviations in the value, and this part of the influence is fixed and can be determined experimentally, so the deviation constant K _deviation is introduced;

V _{Actual liquid volume} refers to the volume of concentrated acid and concentrated alkali required in the actual acid-base neutralization operation;

V _{Theoretical liquid volume} refers to the volume of concentrated acid and concentrated alkali required in the calculation of acid-base neutralization operation;

The K _deviation is verified through repeated neutralization, and the empirical value is 1.09 (related to the diameter, length and wall roughness of the acid-base solution pipeline).

In step S2.2, the pH value is always monitored during the discharge of the waste liquid. When the pH value changes, the recirculation valve 3 is opened, the drain valve 2 is closed, and the waste water pump 6 is then closed.

The invention also discloses a logic setting module for waste water acid-base neutralization control of a waste water acid-base neutralization control method, the logic setting module is set in the PLC program for controlling the operation of waste water acid-base neutralization equipment The set wastewater acid-base neutralization logic can realize automatic closed-loop control), in step S2, the logic setting module performs logical operation to calculate the set amount of the required concentrated alkali solution and the set amount of the required concentrated acid solution,

The logic setting module includes a first submodule and a second submodule;

The first submodule is used to control the PLC program to realize steps S1.2, step S1.3, and step S1.4; the mathematical model formula (calculating the waste water volume) in the step S1.2 is set in the first submodule;

The second sub-module is used to control the PLC program to realize steps S2.1 and S2.2; the mathematical model formula in step S2.1 is set in the second sub-module.

The device described in the present invention is not limited to the examples described in the specific implementation manner. Other implementation manners obtained by those skilled in the art according to the technical solution of the present invention also belong to the technical innovation scope of the present invention.

Claims (9)

1. a waste water acid-base neutralization control method, used for the control of the waste water acid-base neutralization equipment of the chemical water system of nuclear power plant, described waste water acid-base neutralization equipment is provided with waste water pool (16) and also includes with said waste water acid-base neutralization equipment An acid metering box (14) and an alkali metering box (15) connected to each other in the waste water pond (16), the method may further comprise the steps: Step S1, the program calculates the volume V of the _waste water in the waste water pool (16), and stirs the waste water; Step S2, read the pH value of the waste water, when the pH value is <6, calculate the set amount of the required concentrated alkali solution, add the set amount of concentrated alkali solution to the waste water, so that the alkali metering The liquid level of box (15) drops to set value; When described pH value＞9 time, calculate the set amount of required concentrated acid solution, add the set amount of concentrated acid in described waste water, make described acid The liquid level of the metering tank (14) drops to a set value; when 6≤the pH value≤9, the waste water is discharged from the waste water pool (16). 2. A kind of wastewater acid-base neutralization control method as claimed in claim 1, is characterized in that: The waste water acid-base neutralization equipment also includes a liquid inlet pipe (17) and a liquid discharge pipe (18) connected to the waste water tank (16), and the liquid inlet pipe (17) is provided with a liquid inlet valve ( 1), the drain valve (2) and the waste water pump (6) are arranged in series on the drain pipe (18), and the drain valve (2) is close to the outlet end of the drain pipe (18); A pH meter (11) is set on the drain pipe (18) between the drain valve (2) and the waste water pump (6); Also comprising a circulation pipe (19), the top of the circulation pipe (19) is connected on the drain pipe (18) between the drain valve (2) and the pH meter (11); The bottom end of the circulation pipe (19) is provided with an agitator (13), and the agitator (13) is located in the waste water tank (16); the circulation pipe (19) is provided with a recirculation valve (3) ; The wastewater tank (16) is provided with a wastewater level gauge (12); It also includes an acid metering box (14) that is provided with a first acid inlet pipe (20), a second acid inlet pipe (22) and an acid liquid level gauge (9), and the second acid inlet pipe (22) is connected with the acid liquid level gauge (9). The waste water pool (16) is connected; the first acid inlet pipe (20) is provided with a first acid inlet valve (4), and the second acid inlet pipe (22) is provided with a second acid inlet valve (8 ); Also include the alkali metering box (15) that is provided with the first alkali inlet pipe (21), the second alkali inlet pipe (23) and the lye level gauge (10), the second alkali inlet pipe (23) is connected with the The waste water pool (16) is connected; the first alkali inlet pipe (21) is provided with a first alkali inlet valve (5), and the second alkali inlet pipe (23) is provided with a second alkali inlet valve (7 ); There are multiple waste water pools (16), which serve as backups for each other. When one waste water pool (16) performs an acid-base neutralization operation, the remaining waste water pools (16) can receive the waste water. 3. A kind of waste water acid-base neutralization control method as claimed in claim 2, is characterized in that, in described step S1, specifically comprises: Step S1.1, the operator on duty manually triggers the waste water acid-base neutralization procedure; Step S1.2, closing the liquid inlet valve (1) and the liquid discharge valve (2), and opening the recirculation valve (3); Step S1.3, open the first acid inlet valve (4) and the first alkali inlet valve (5), and close the first acid liquid level gauge (9) when a high liquid level alarm occurs. An acid inlet valve (4); when a high liquid level alarm occurs in the lye liquid level gauge (10), close the first alkali inlet valve (5); Step S1.4, start the wastewater pump (6), and stir and mix the wastewater in the wastewater pool (16) with the agitator (13) until the pH value is stable, and the pH value is refers to the pH value shown in the pH table (11). 4. A kind of waste water acid-base neutralization control method as claimed in claim 3, is characterized in that, in described step S2, specifically comprises: Step S2.1, judging according to the execution conditions of the pH value, when the pH value is <6, open the second alkali inlet valve (7), and add a set amount of lye to the waste water pool (16) ; when the pH value > 9, open the second acid inlet valve (8), and start to add a set amount of acid solution to the waste water tank (16); when 6≤the pH value≤9, Open the drain valve (2), close the recirculation valve (3), and the waste water pool (16) starts to discharge the waste water; Step S2.2, when the waste water level gauge (12) has a low liquid level alarm, turn off the waste water pump (6); Step S2.3, the waste water pool (16) is in standby state. 5. A kind of waste water acid-base neutralization control method as claimed in claim 4, is characterized in that: in said step S1.2, make all the said waste water tanks (16) that carry out acid-base neutralization operation The waste water is in a relatively stable state, and according to the liquid level of the waste water, the volume of the waste water is calculated through a mathematical model formula; Wastewater volume V _{waste water} = S _{waste water pool} × H _{waste water} ; S _{waste water} refers to the sectional area of described waste water pool (16); H _{waste water} refers to the liquid level height of waste water. 6. A method for controlling acid-base neutralization of waste water as claimed in claim 5, characterized in that: in said step S1.3, said acid metering box (14) and said alkali metering box (15) It contains enough concentrated acid and concentrated alkali for an acid-base neutralization operation; during the acid-base neutralization process, if the acid metering box (14) or the alkali metering box (15) has a low liquid level alarm , then the concentrated acid or the concentrated alkali will be automatically replenished in the acid metering box (14) or the alkali metering box (15). 7. A kind of waste water acid-base neutralization control method as claimed in claim 6, is characterized in that, in described step S2.1, by mathematical model formula, calculate The concentration of hydrogen ion substance and the concentration of hydroxide ion substance and the volume of the concentrated alkali and the concentrated acid of the required amount, and control the concentrated acid and the concentrated alkali by calculating the liquid level height of the waste liquid The required amount; the specific mathematical model formula is as follows: Concentration of hydrogen ion species in concentrated acid:

Concentration of hydroxide ion species in concentrated alkali:

in, ρ _{Concentrated acid} refers to the density of concentrated acid at 20°C; ρconcentrated _alkali refers to the density of concentrated acid at 20°C; W% refers to the mass fraction of solute in concentrated acid or the mass fraction of solute in concentrated alkali; M _{concentrated acid} refers to the molar mass of concentrated acid; M _{concentrated alkali} refers to the molar mass of concentrated alkali; When reaching the pH neutral point, when the pH value is 7, [H ⁺ ]=[OH ^- ]=1×10 ^-7 mo/L; Before carrying out acid-base neutralization operation, described concentrated acid and described concentrated alkali first flow into described acid metering box (14) and described alkali metering box (15), pass through described acid metering box (14) and described The liquid level height of alkali metering box (15) controls the required consumption of described concentrated acid and described concentrated alkali, and described acid metering box (14) and described alkali metering box (15) are standard cylinder type;

When the waste liquid pH<7, add alkali for neutralization, the volume of the concentrated alkali needs to be added:

When the waste liquid pH>7, add acid to neutralize, need to add the volume of described concentrated acid:

Waste liquid pH refers to the pH value that described pH meter (11) shows;

refers to the concentration of hydrogen ion substances in the waste water before the acid-base neutralization operation,

Refers to the concentration of hydroxide ion substances in the waste water before the acid-base neutralization operation,

refers to the concentration of hydrogen ion substances in the wastewater in a neutralized state,

Refers to the concentration of hydroxide ion substances in the wastewater in a neutralized state;

Refers to the concentration of hydrogen ion species in concentrated acid;

Refers to the concentration of hydroxide ion species in concentrated alkali; Also includes the bias constant K _bias

V _{Actual liquid volume} refers to the volume of concentrated acid and concentrated alkali required in the actual acid-base neutralization operation; V _{Theoretical liquid volume} refers to the volume of concentrated acid and concentrated alkali required in the calculation of acid-base neutralization operation; The K _bias is 1.09. 8. A method for controlling acid-base neutralization of waste water as claimed in claim 7, characterized in that: in said step S2.2, during the waste liquid discharge process, the pH value is always monitored, when the pH value When a change occurs, open the recirculation valve (3), close the drain valve (2), and then close the waste water pump (6). 9. The logic setting module for a kind of waste water acid-base neutralization control of a kind of waste water acid-base neutralization control method as claimed in claim 8 is characterized in that: The logic setting module is set in the PLC program that controls the operation of the waste water acid-base neutralization equipment. In the step S2, the logic setting module performs logic operations to calculate the set amount of the required concentrated alkali solution and the required The set amount of concentrated acid solution required; The logic setting module includes a first submodule and a second submodule; The first submodule is used to control the PLC program to implement steps S1.2, S1.3, and S1.4; the mathematical model formula in the step S1.2 is set in the first submodule; The second submodule is used to control the PLC program to implement step S2.1 and step S2.2; the mathematical model formula in the step S2.1 is set in the second submodule.

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